My vote for the most reliable bolt feeder is the 505 GIBBS. Mine are both left handed Ryan Breeding rifles.
Sincerely,

Jeffeosso and hidalgo mentioned the .400 H&H. Hidalgo even went so far as to say his .400 H&H feeds just as smoothly as his .375 H&H. I have to agree with that assessment but I have shot only a very small sampling of the entire universe of big bore cartridges..

We must not forget to consider the rifle. The slickest feeding .4XX+ cartridge in a rough cycling rifle is no better or worse than a rough feeding .4XX+ cartridge in the slickest cycling rifle. Further, some cartridges are suitable for use in some rifles and others are not. As a result, we may find ourselves comparing the feeding of one cartridge in one rifle against the feeding of a different cartridge in a different rifle. That only leaves us to ponder whether it was the cartridge, the rifle, or the unique combination of the two that made the operation so slick the cartridge almost loaded itself.

I bet this will get to feed and feed easier than the 400 HH. The 410-375 HH AKA 400 Karamojo

boom stick,
If I weren't working on a .410/404J 6-shooter,
I would be sorely tempted by your 400 Karamojo 7-shooter.

Just be careful of typos, "400 Karamofo" is all too easy an accident.

I got all 7 of those dummies to fit in a CZ 550 Magnum and feed like greased lightning.
Slicker than with the .458 Lott that the rifle was chambered for, having originally been a .458 WinMag.
Of course, D'Arcy Echols did not do the feed job.

I would prefer this version of the .410/.375 H&H, or maybe better, your ghost-shouldered version, versus the proprietary 400 H&H.

There will be no mucked-up barrel versus bullet specs if you go with a Douglas .410/.400 barrel.
Somehow H&H screwed the pooch on that.
But what is a thou or two amongst extended pinky fingers, eh?





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